The present invention relates to a cutting insert, especially a metal cutting insert having high wear resistance and excellent chip breaking properties.
For the machining of several non-ferrous alloys like brass, magnesium and aluminum, diamond is the best tool material.
Cutting inserts formed with diamond include (i) so-called PDC (polycrystalline diamond compact) comprising a cemented carbide cylindrical base or disk B with a diamond layer A applied usually at such high temperature and pressure where diamond is in the stable phase (FIG. 1), and (ii) polygonal inserts provided with diamond bodies in a corner or along an edge generally fastened by brazing (FIGS. 2 and 3). Depicted in FIG. 2 is a triangular base D with a diamond body E in a corner thereof; depicted in FIG. 3 is a triangular base F with an elongated diamond body G extending along one edge of the base.
Another type of tool material produced at a similar process is cubic boron nitride (cBN) which is very well suited for machining hardened steel, chilled cast iron and cast iron at elevated speeds.
A common disadvantage with such inserts is the lack of chip breaking capabilities since no chip breakers, or only very simple chip breakers, can be provided.